Effect of election

If the spouse of an individual described in paragraph (1)(A) elects to file a joint return under subsection (a) for a taxable year, then, until such election is revoked—

(A) such election shall be valid even if such individual died before the beginning of such year, and

(B) except for purposes of section 692 (relating to income taxes of members of the Armed Forces, astronauts, and victims of certain terrorist attacks on death), the income tax liability of such individual, his spouse, and his estate shall be determined as if he were alive throughout the taxable year.